Warp control in power looms



Jan. 27, 1942. A. MOES'SINGER I 2,271,202

WARP CONTROL IN POWER LOOMS Filed April 5, 1939 s Sheets-Sheet 1 ALBERT MgJJ/NE-R Jan. 27, 1942. A. MOESSINGER 2,271,202

WARP CONTROL IN POWER ,LOOMS Filed April 5, 1939 s Sheets- Sheet 2 5 JPm/vc FORCE) 1.55.

5 INVENTOR.

J'wuva' F LEVER gave/15s:

ALaEkr MESJING'ER. I

Jan. 27, 1942. A. MOESSINGER 2,271,202

WARP CONTROL IN POWER LOOMS Filed April 5, 1939 s Sheets-$heet 3 INVENTOR.

A1. sERr/WoEss/NcE/e.

Patented Jan. 27, 1942 UNITED STATES PATENT OFFICE wmi CONTROL IN rowan LOOMS Albert Moessinger, Winterthur, Switzerland, as-

aignor to Gebrneder Sulzer, Aktiengeselischaft, 'Winterthur, Switzerland Application April 5, 1939, Serial No. 266,099

' In Switzerland May 23, 1938 22 Claims.

The present invention relates to a warp supply and tensionlng mechanism in looms for weaving more particularly to the "passive type of warp beam, 1. e. which is independent of the;

changing diameter of said beam.

It is an objectof the present invention to provide a mechanism of the type set forth in which the warp beam is provided witha' brake which brake is locked together with the warp thread tensionlng beam during the beat.

According to the present invention the movements of the warp beam depend .on a brake which is connected with the warp beam by means of a reducing gear'and the warp threads are held under a desired tension by means of a warp tensioning beam. The tensioning beam and the brake are locked by the loom drive during the beat in the position in which they are before the beat and the brake is subjected to the action of the tensionlng beam between the beats. Locking of the warp beam may be eifected before or at least simultaneously with the locking of the tensionlng beam. Locking of the brake and the tensionlng beam may be effected by pressing the brake shoes for the tensioning beam against the brake disc also. In this case it is preferred that the line interconnecting the braking point of said brake and the axis of the tensionlng beam and the line connecting the braking point and the center of the brake enclose an angle of approximately 90. Locking of the warp beam may be accomplished by means of brake shoes which are parallel to the plane in which the lever moves which supports the tensioning beam. These brake shoes may simultaneously intensify the locking of the tensionlng beam support lever.

The brake may also be locked by periodic actuation of the brake band by means of the loom drive.

The spring acting on the tensionlng beam support lever maybe so arranged that the angle formed by the line interconnecting the point of action of saidspring on said lever and the fulcrum of said lever and the line of direction of the spring action is smaller than The initial tension of said spring is preferably equal to 1' tan sin 4:, whereby r is the radius between the fulcrum of the tensionlng beam support lever and thepoint of action of the tensionlng spring on said lever and #1 is the medium value of the above defined angle which should not exceed 60. The adjustment of the moment of torsion exerted on the axis of the tensionlng beam is preferably accomplished by displacement of the point of action of the tensionlng spring on the tensionlng beam support lever along a radius extending from the fulcrum of said lever. This displacement may be effected in aslot which is inclined approximately 45 with respect vto the direction of the force of the tensionlng spring. The slot may extend radially from the fulcrum of the tensionlng beam support lever and the tensionlng spring may be so mounted that its direction of action is moved parallel to itself when the spring is moved for changing the moment of torsion acting on said lever. If the direction of'action of the tensionlng spring on the tensionlng lever remains parallel to itself when the warp tension is changed the angle 1/ which is formed by the line of direction of action of the tensioning spring and the line along which the stationary end of the spring moves is 1 tan o arc cot (tan 4 lever a moment of torsion in the opposite direction of the moment of torsion exerted by the brake spring the line of direction of action of the brake spring and the line between the point of action of the brake spring on the tensionlng lever on the fulcrum of said lever should form an angle 5 which is smaller than 30. According to the, present invention the same spring may be used for tensioning the tensionlng lever of the tensioning beam and for tensionlng and actuating the brake.

Having now described in a general way some of the objects and principles of the present inventipn, I nowproceed in describing some specific embodiments of the present invention In the drawings:

Figure 1 is a diagrammatic side view of a mechanism according to the present invention.

Figure 2 is a top view of a detail of the mechanism shown in Fig. 1.

Figure 3 is an isometric showing of another detail of the mechanism shown in Fig. 1.

Figure 4 is a diagrammatic side view of a modified mechanism according to the present invention.

Figure 5 is a diagrammatic rear view of certain parts of the mechanism shown in Figure 4.

Figure 6 is a large scale view of a detail of the tensioning means and of amodification of a brake arrangement in amechanism according to the present invention.

Figure 7 is a diagram showing spring forces acting on the brake of a mechanism according to the present invention.

Figure 8 is a large scale view of a modified tensioning arrangement according to the present invention.

Figure 9 is a large scale view of another modification of a tensioning means arrangement in a mechanism according to the present invention.

Referring more particularly to Figs. 1 to 3 of the drawings, 2 designates the warp beam from which the warp threads I are unwound; threads I pass over the tension roller or beam 4 before forming the shed with its point 3. The weft threads are pressed into the shed by means of the reed 3 whereby the material is produced which is passed over the breast beam 5 and wound to a cloth winding roller. The tensioning beam 4 rotatably rests at both ends on pivots 8 which pivots are supported by means of tensioning beam support levers 1. Levers 1 are rigidly interconnected by means of a tube or rod 6 and swing about the pivots 9. At least one of the levers 1 is connected with a brake comprising brake band i4, tensioning means I5 which may be connected to one of the pivots 8,

and a brake drum It. At least one of the levers 1 is held under tension by means of a spring ll one end of which is stationary and the other acts on the connecting rod in which is adjustably and movably connected with the lever 1. The spring or springs 15 is or are preferably so positioned that the momentum acting on the tensioning levers is about the same at all normal possible positions of the lever.

Brake drum I6 is rigidly connected with a shaft l9 which rotatably rests in bearings I1 and l8. As can be seen in Fig. 3 shaft I9 also carries a disc 20 and a pinion 2|. Pinion 2| engages a tooth wheel 22 which is rigidly connected with the warp beam 2. Each revolving motion of the warp beam is therefore transmitted to shaft l9 and brake disc 16. The warp beam shaft 23 rests in two bearings.

At least one of the tensioning beam levers 1 is provided with an extension 1' to which two plate members 24 are connected between which part of the disc-20 is located. A stirrup or inverted U member 25 extends around theplate or brake shoe members 24. The two legs of member 25 are resiliently pressed together and. towards the plate members 24 which latter are then pressed .onto disc 20 by means of a-bolt 21 and a spring 26. The stirrup member 25 is connected with a stationary part 25 and interlocks the warp beam 2 and the tensioning beam 4. The two legs of member 25 can be forced apart against the action of spring 26 whereby the plates 24 are removed from disc 20 so that there is no interlocking of the two beams 2 and 4. Forcing apart of the legs of member 25' is accomplished by a cam 3| which is connected to one end of a rod 28 the other end of which carries a lever 29 which is engaged and operated by a cam 39.

If the lever 1 is turned in the direction of arrow l3 because. of a shortening of the warp threads the brake band I4 is loosened and warp beam 2 is freed and turns in the direction of arrow 32 under the influence of the tensioned warp threads I. The free length of the warp threads between the warp beam 2 and the shed 3 is then increased whereby tensioning lever 1 moves clockwise and the brake effect on beam 2 is increased.

In Figures 4 and 5 an embodiment of the present invention is shown in which the tensioning beam 34 is locked independently from the warp beam 2. I

In the machine according to Figs. 4 and 5 the warp threads I running off the warp beam 2 pass over the tensioning beam 34 which rotates about the pivots 33. These pivots are supported by -means of tensioning beam support lever 35 which swings about axle 36. Fulcrums 33 and 36 are preferably provided with ball, ro1ler-, or needle-bearings so that the mechanism follows all movements of the warp threads without changing the tension thereof. Lever 35 has an extension 31 which carries a weight 38 which is displaceable along said extension. The end of lever arm 31 is situated between two flat members 39 whichare resiliently held together and are pressed against the extension 31 by means of bolt 41 and spring 40. The fiat members 39 are interconnected and fixed to a stationary part 43 of the loom by means of a bolt 42. The fiat members 39 with their interconnection form an inverted U similar to part 25 in the embodiment of the present invention shown in Figs. 1 to 3. The legs of the U which are resiliently forced together can be spread apart by a wedge member 45 which is disposed at the end of a lever 45' which swings about a stationary fulcrum 44. The wedge member 45 is provided with a roller 48 which rests on a cam 41 which cam is keyed to shaft 48; the latter is driven by the main drive of the loom. Cam 41 is thus adapted to periodically swing lever 45 and wedge 45 upward and in between the members 39 thereby disengaging said members from lever arm 31 and unlocking lever 35, 31.

Shaft 48 carries also a crank or eccentric 49 by means of which the warp beam 2 is periodically locked. For this purpose a rod 50 is connected with eccentric 49; rod 50 is resiliently connected by means of spring 5| and shackle 52 to one end of the brake band 14. The other end of the brake band is connected with a threaded bolt 54 which rests, through the agency of spring 53, on the lever 35 which holds and supports the tensioning beam 34. The brake band l4 engages the brake drum l6 which acts on the warp beam 2 through the intermediary of gear wheels 2| and 22.

The action of the brake depends on the position of lever 35 and also on the position of cam 41. Furthermore, the tension of the brake band is increased periodically during each beat of the reed because of the connection of one end of the band with the crank 49 which end, in the embodiment shown in Figs. 1 to 3, is fixed.

duced by the tensioning spring 69 on the lever 1 should be constant, as far as possible. In order to avoid the use of too large a spring 60 the following construction is proposed; c is the angle enclosed by the direction 68 in which the force of the spring 60 acts and the connecting line between the -fulcrum 9 of lever I, I' and point 69 at which said force acts on lever I, I and which point is the point of angle (p. The influence of the characteristic, i. e. the change of power of spring 60, for example, per inch elongation depends on the size of angle This angle can be so chosen that there is a minimum change of the torque produced by spring 60 on lever 1. /If angle it amounts to 45 the initial tension of spring 60 must be 1' sin 45 where r designates the radius or distance of point 63 from fulcrum 9. This distance is made adjustable.

If the tension of the warp threads is changed solely by tensioning of spring 60 the initial tension is not r sin 45 and the moment of torsion acting on the tensioning beam 4 is not independent from the position of said beam. The mechanism shown in Fig. 6 assures a satisfactory control of the warp thread tension. The lever 1, 1' is provided with a slot 6| the longitudinal axis of which passes through the center of fulcrum 9. A threaded bolt 62 is provided in said slot which carries a nut 63 having a pivot attached thereto for movably holding one end of rod 64. On the other end of rod 64 acts one end of the spring 60. The other end of said spring rests on the washer 65 which washer rests on stationary member 66 which is provided with a slot 61 for accommodating the rod 64. If it is desired to increase the tension of the warp screw 62 is revolved for moving nut 69 outward, i. e. for increasing radius r and washer 65 is moved upward on member 66 until rod 64 is again in horizontal position. If, as shown in Fig. 6, angle is 45 member 66 is fixed to a stationary part of the loom in a position perpendicular to rod 64. The initial tension of spring 69 is then 1' sin 45 at all tensions of the warp threads. If angle is not 45 washer 65 does not move in a plane which is perpendicular to rod 64.

In order to eliminate the influence of the brake spring 10 a spring of such character'is chosen that the moment of torsion acting on the tensioning beam remains constant as long as the changes of angle 5 are minor. Angle 5 is formed by the line of direction of the force of spring 10 acting on pivot 8 and the connecting line between the center of pivot 9 and the center of fulcrum 9.

The brake force is much reduced at diminishing diameter of the warp beam and a large movement of tensioning lever I is therefore desired. This is made possible by means of the following mechanism: Spring 10 is so designed as to. produce the desired initial force at an angle 18. When lever 1 moves to its extreme tensioning position the force of spring I0 changes to'produce the maximum desired brake effect. Brake band 12 is not only subjected to the influence of spring II! but also to the influence of spring II which may be replaced by a weight. The initial tension of spring II is equal to the smallest force produced by Spring 10. The difference between the forces of springs 10 and 'H acts .on the brake band"; this difference varies between a zero value and the maximum brake force,

The actions of springs 10 and H are diagrammatically shown in Figure 7. In this figure the ordinates represent the force of the springs, for example in pounds, and the abscissae the movement or swing of the tensioning lever I, for example in inches. The inclined line I0 illustrates the force produced by spring 10 at various positions of the tensioning lever "I; the horizontal line II shows the force produced by spring H; the latter force is constant and the same at all positions of lever I because one end of spring .'II is stationary and the other connected with brake band I2, 1. e. also stationary and the length of spring II is always the same. between the forces 10' and I l acts on brake band 12. The character of spring 10 which is indicated by the inclination of line 10 is such that at the maximum possible movement s of the tensioning beam 'l the force acting on the brake band varies from zero to a value designated by letter p where the force p is the maximum desired brake force.

The relation between the initial tension of the spring for producing the desired warp tension and the. angle a at which said spring acts on the tensioning lever I is more clearly illustrated in Figs. 8 and 9. In Fig. 8 numeral designates the fulcrum of a tensioning lever 80 the end of' which rotatably supports the'tensioning beam 92,

by means of pivot 9|. Lever 80 is provided with an extension 93 which has a plurality of notches 94 for receiving one of the hooked ends of the tensioning spring 95. The axis 99 of spring 95 and the radius r between the center of fulcrum "and the point where spring 95 is hooked to extension 93 form an angle 5. The other end of spring 95 is. also hook-shaped and hooked into one, of the notches 91 of a stationary member 96. Notches 91 are disposed along a line 99 which line encloses with the axis of the tensioning spring an angle 1/. The moment ottorsion M acting on the lever 80 can be defined by the following equation:

wherein it is a constant; if expression is used for the value a the change of the moment of torsion at a change of the angle 4 is:

-f k r cos '-r (cos sin The change isa minimum when dM 71? equals zero i. e. when cos 2 o 008 iii If angle 4: is 45, k is zero and a equals r sin 45.

This is the case in the mechanism shown in Fig. 6. In the mechanism shown in Fig. 8,

or a=r tan 4 sin The difference angle o is larger than 45; since his in proportion to r the end of the spring jnoves on a straight line having the inclination:

1 In Fig. 8 the total initial elongation or tensionof spring 85 is 1' cos +k and the length of the untensioned spring is designated by letter b.

with the arrangement according to the present invention it is possible to adjust the tension of the warp threads I so that this tension remains equal and independent from changes of angle 45 and that without changing the spring.

.Figure 9 illustrates another embodiment of V the present invention. The tensioning lever 88 tion between the initial tension a of spring 85 and the angle formed by the center line of the spring and the line connecting the spring .end

and fulcrum 82:

a=r tan sin" where the distance a is measured from the involute 88 extending from fulcrum 8-2.

In th embodiment of the invention according to Fig. 9 spring 85 serves for controlling the brake force of band brake 88. A spring 81 is provided the strength of which is greater than that of spring 85. If the warp threads [are too long tensioning beam 88 swings upward about fulcrum 82, the tension of spring 85 is reduced and the braking efiect which is the dinerence between the constant force of spring 81 and the variable force of spring 85 is increased.

Adjustment of the brake force may be made by manipulation of nuts 88.

While I believe the above described embodiments of my invention to be preferred embodiments, I wish it to be understood that I do not desire to be limited to the exact details of design and construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

l. A warp thread supply and tensioning mechanism for power looms including a loom drive, a warp beam, a warp tensioning beam, a brake connected with said warp beam, a periodically acting locking mechanism connected with said tensioning beam and with said loom drive and with said brake and periodically. locking said tensioning-beam and said brake in their positions before the beat, and connecting means connected with said brake and with said tensioning beam for rendering the operation of said brake dependent on the position of said tensioning beam when said locking mechanism is unlocked.

2. A warp thread supply and tensioning mechanism for power looms including a loom drive, a warp beam, a warp tensioning beam, a brake connected with said warp beam, a periodically acting locking mechanism connected with said tensioning beam, with said loom drive, with said brake and with said warp beam and periodically locking said tensioning beam, said brake and said warp beam, and connecting means connected with said brake and with said tensioning beam for rendering the operation of said brake dependent on the position of said tensioning beam when said locking mechanism ,is unlocked.

3. A warp thread supply and tensioning mech-' anism for power looms including a loom drive, a warp beam, a warp tensioning beam, a movable warp tensioning beam support having locking means connected therewith, a brake connected with said warp beam and being lockingly engaged by said locking means, a periodically .acting unlocking mechanism connected with said loom drive and,periodically unlocking said locking means and disengaging said locking means from said brake, and connecting means connected with said support and with said brake for rendering the operation of said brake dependent on the position of said tensioning beam when said locking means are unlocked.

4. A warp thread supply and tensioning mechanism for power looms including a loom drive, a warp beam, a warp tensioning beam, a warp tensioning beam support lever having locking means connected therewith, a brake having a brake diseoperatively connected with said warp beam and being adapted to be lockingly engaged by said locking means, a periodically acting unlocking mechanism connected with said loom drive and periodically unlocking said locking means and disengaging said locking means from said brake, said brake having a brake band engaging said brake disc and having an end connected with said support lever for rendering the operation of said brake dependent on the position of said support lever when said locking means are unlocked. 5. A warp thread supply and tensioning mech-,

beam and having a disc member rotating in the same plane as said support moves and adapted to be lockingly engaged by the prongs of said forked end, a periodically acting unlocking mechanism connected with said loom drive and periodically disengaging the prongs of said forked end from said disc, and brake means connected with said support and with said brake for rendering the operation of said brake dependent on. the position of said support when said locking means are unlocked.

6. A warp thread supply and tensioning mechanism for power looms including, in combination, a warp beam, a warp tensioning beam, the warp threads running of! from said warp beam passing over said tensioning beam before forming the shed, a tensioning beam support adapted to swing about a stationary fulcrum and swingably supporting said tensioning beam, a guide means longitudinally displaceably connected with said support, a source of power connected with said guide means and swinging said support for pressing said tensioning beam against and thereby tensioning the warp threads, the magnitude of tensioning power depending on the position of said guide means on said support and the line of direction of action of said source of power on said support and the line connecting the point of action of said source on said support and the fulcrum of said support forming an angle which is smaller than 60 and which remains substantially the same at all positions of said guide means relatively to said support.

7. A warp thread supply and tensioning mechanism for power looms including a warp beam,

i 1 amnaoa a warp tensioning beam, the warp threads running of! from said warp beam and passing over said tensioning beam before forming the shed, a tensioning beam support swinging about a stationary fulcrum and swingably supporting said tensioning beam,'a spring connected with 'said support and swinging said support and pressing said tensioning beam against and thereby tensioning the warp threads, the initial elongation of said springbeing rsin tanwhereby s isthe angle formed by the line of direction of action of said spring on said support and the line connecting the point of action of said spring on said support and the fulcrum of said support, and r is the distance between said point of action and said fulcrum.

8. A warp thread supply and tensioning mech anism for power looms including a warp beam, a warp tensioning beam, the warp threads running off from said'warp beam passing over said tensioning beam before forming the shed, a tensaid tensioning beam, said support having a longitudinal guide, and a tensioning means connected with and being displaceable along said guide and swinging said support and pressing said tensioning beam against and thereby tensioning the warp threads, the line of direction of action of said tensioning means on said support forming with the longitudinal axis of said guide an angleof substantially 45.

10. A warp thread supply and tensioning mechanism for power looms including a warp beam, a warp tensioning beam, the warp threads running off from said warp beam passing over said tensioning beam before forming the shed, a tensioning beam support adapted to swing about a stationary fulcrum and swingably supporting said tensioning beam, said support having a longitudinal guide extending radially from the fulcrum of said support, and a tensioning means having an end connected with and being displaceable along said guide and swinging said support andpressing said tensioning beam against and thereby tensioning the warp threads, and having a stationary part which is movably connected with a stationary part of said loom; the'line of action of said tensioning means moving parallel to itself upon displacement of said end of said tensioning means along said guide and of said stationary part.

11. A warp thread supply and tensioning mechanism for power looms including 'a warp beam, a warp tensioning beam, the warpthreads running off from said warp beam-and passing over said tensioning beam before forming the shed, a tensioning beam support swinging about sioning beam support adapted to swing about a tensioning means connected with a stationary part of saidloom and with said actuating means.

12. A warp thread supply and tensioning mechanism for power looms including a warp beam, a warp tensioning beam, the warp threads running off from said warp beam and passing over said tensioning beam before forming the shed, a tensioning beam support swinging about a stationary fulcrum and swingably supporting said tensioning beam, a tensioning means connected with said support and swinging said support and pressing said tensioning beam against and thereby tensioning the warp threads, a brake connected with said warp beam, brake actuating means connected with said brake and with said support, the direction of action ofsaid actuating means being substantially opposite to that of said tensioning means and including with the line interconnecting the point of action of said support on said actuating means and said fulcrum an angle which is smaller than 13. A warp thread supply' and tensioning mechanism for power looms including a warp beam, a warp tensioning beam, the warp threads running off from said warp beam and passing over said tensioning beam before forming the shed, a tensioning beam support swinging about a stationary fulcrum and swingably supporting said tensioning beam, a brake connected with said warp beam, and a tensioning and brake actuating means connected with said support and with said brake and actuating said brake and also swinging said support and pressing said tension ing beam against and warp threads.

14. A warp thread said tensioning beam, a brake connected with said warp beam, brake actuating means con-,

bination, a m drive, -a warp beam, a warp tensioning ,beam, a tensioning beam support adapted to swing about a fulcrum and swingably supporting said tensioning beam, a source of power connected with saidsupport and swinging said support for pressing said tensioning beam against and thereby tensioning the warp threads,

the line of direction of action of said source of power on said support and the line connecting the point of action of said source on said support and the fulcrum of said support forming an angle which is smaller than 60, a periodically acting locking mechanism connected with said tensiening beam and with said loom drive and periodically locking said tensioning beam in its position before the beat.

15. A warp thread 'supply and tensioning mechanism for power looms including a warp beam, a warp tensioning beam, the warp threads running off from said' warp beam and passing over said tensioning beam. before forming the shed, a tensioning beam support swinging about a stationary fulcrum and swingably supporting said tensioning beam, a tensioning means connected with said support and swinging said support and pressing said tensioning beam against and thereby tensioning the warp threads, a brake connected'with said warp beam, brake actuating means connected with said brake and with said support and adapted to exert torque thereon, the direction of action of the torque effectedby said actuating means on said support being the same as that of said tensioningmeans.

16; A warp thread supply and tensioning mechanism' for power looms including a warp Y beam, a warp tensioning beam, the warp threads nected with said brake and said support, and a 15 running off from said. warp beam and passing over said tensioning beam before forming the thereby tensioning the supply and tensioning shed, a tensioning beam support swinging about and therebytensioning the warp threads, a brake' connected with said warp beam, brake actuating means connected with said brake and with said support and adapted to exert torque thereon, the direction of action of the torque effected by said actuating means on said support being substantially opposite to that of said tensioning means.

17. A warp thread supply and tensioning mechanism for power looms including a warp beam, a warp tensioning beam the warp threads running off from said warp beam and passing overisaid tensioning beam before forming the shed, a tensioning beam support swinging about a stationary fulcrum and swingably supporting said tensioning beam, a brake connected with said warp beam, brake actuating means connected with said brake and said support, and a spring interposed in said actuating means between said support and said brake, the line of direction of action of said brake actuating means on said support and the line connecting the point of action of said brake actuating means on said support and the fulcrum of said support forming an angle which is smaller than 30.

18. A warp thread supply and tensioning mechanism for power looms including, in combination, a warp beam, a warp tensioning beam, the warp threads running oil from said warp beam passing over said tensioning beam before forming the shed, a tensioning beam support adapted to swing about a stationary fulcrum and swingably supporting said tensioning beam, a guide means movably connected with said support and being displaceable along a line extending substantially radially from said stationary fulcrum, a source of power connected with said guide means and swinging said support for pressing said tensioning beam against and thereby tensioning the warp threads, the magnitudeoi' tensioning power depending on the position of said guide means on said support and the line of direction of action of said source of power on said support and the line connecting the point of action of said source on said support and .the fulcrum of said support forming an angle which is smaller than 60 and which remains substantially the same at all positions of said guide means relatively to said support.

19. A warp thread supply and tensioning mechanism for power looms including, in combination, a warp beam, a warp tensioning beam, the warp threads running off from said warp beam passing over said tensioning beam before forming the shed, a tensioning beam support adapted to swing about a stationary fulcrum and swingably supporting said tensioning beam, a guide means longitudinally displaceably connected with said support, a source of power connected with said guide means and swinging said support for pressing said tensioning beam against and thereby tensioning the warp threads, the magnitude of tensioning power depending on the position of said guide means on said support and the line of direction of action of said source of power on said support and the line connecting the point of action of said source on said support and the fulcrum of said support forming an angle which is smaller than 60 and which remains substantially the same at all positions of said guide means relatively to said support, and

arresting means operatively connected with said tensioning beam support and with the loom drive and including periodically acting arresting means actuating means periodically arresting said tensioning beam support in its position before the beat.

20. A warp thread supply and tensioning mech- V ing over said tensioning beam before forming the shed, a tensioning beam support adapted to swing about a stationary fulcrum and swingably supporting said tensioning beam, a guide means longitudinally displaceably connected with said support, a source of power connected with said guide means and swinging said support for pressing said tensioning beam against and thereby tensioningthe warp threads, the magnitude of tensioning power depending on the position of said guide means on said support, the line of direction of action of said source of power on said support and the line connecting the point of action of said source on said support and the fulcrum of said support forming an anglewhich is smaller than and which remains substantially the same at all positions of said guide means relatively to said support, brake means connected with said warp beam, and brake means actuating means connected with said brake means and with said tensioning beam support and being actuated byporting said tensioning beam, a guide means iongitudinally displaceably connected with said support, a source of power connected with said guide means and swinging said support for pressing said tensioning beam against and thereby tensioning the warp threads, the magnitude of tensioning power depending on the position of said guide means on said support and the line of direction of action of said source of power on said support and the line connecting the point of action of said source on said support and the fulcrum of said support forming an angle which is smaller than 60 and which remains substantially the same at all positions of said guidemeans reiatively to said support, arresting means operatively connected with said tensioning beam support and with the loom drive and including periodically acting arresting means actuating means periodically arresting said tensioning beam support in its position before the beat, brake means connected with said warp beam, and brake means actuating means connected with said brake means and with said tensioning beam support and being actuated by said support whenever said tensioning beam is moved in a direction for tensioning the warp threads whereby rotation of said warp beam is reduced whenever the warp threads are tensioned.

22. A warp thread supply and tensioning mechanism for power looms including, in combination, a warp beam, a warp tensioning beam, the warp threads running ofi from said warp beam pass- V 2,271,202 ing over said tensioningbeam before forming the shed, a tensioning beam support adaptedto swing 4 about a stationary fulcrum and swingably supporting said tensioning beam, a guide means longitudinally displaceably connected with said support, a source of power connected with said guide means and swinging said support for pressing said tensioning beam against and thereby tensioning the warp threads. the magnitude of tensioning power depending on the position of said guide means on said support and the line of direction oi action of said source or power on said support and the line connecting the point or action oi! said source on said support and the fulcrum of said support forming an angle which is smaller than 60 and which remains substantially the same at all positions oi! said guide means relatively to said support, brake means connected with said warp beam; and brake means actuating means connected with said brake means and with said tensioning beam support and being actuated by said support whenever said tension beam is moved in a direction for tensioning' the warp threads whereby rotation of said warp beam is reduced whenever the warp threads are tensioned, and arresting means operatively connected with said tensioning beam support, with said warp beam and with the loom drive and includingperiodically acting arresting means actuating means periodically arresting said tensioning beam support and said warp beam in their position before 15 the beat.

ALBERT MOESSINGER. 

